Great comment. I strongly encourage providers to seek milestone payments on any jobs that are going to span more than a week or so of time. It’s another good way to mitigate risk.

oDesk does support milestone payments, and buyers can submit milestone payments at any time on a Fixed Price project. (They can also submit bonuses on hourly jobs).

-Josh Breinlinger
oDesk

I’ve done quite a bit of fixed-price work, not so much on oDesk, and sometimes it’s worked very well for me, other times less well.

One thing that worked well for me on a large project was getting partial payments as I completed sections of the work. Admittedly this was on a site that did support escrow. I’d finish a section, tell the buyer who would put a partial payment into escrow. Then I’d email them that one section, they’d release the partial payment and we’d repeat. It worked very well.

Even without escrow, try to get “milestone” payments– not just an upfront but part payments as you do the work.

It makes large fixed-price jobs much easier to deal with.